/* Definition for thread-local data handling.  nptl/x86_64 version.
   Copyright (C) 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _TLS_H
#define _TLS_H 1

#ifndef __ASSEMBLER__
# include <asm/prctl.h> /* For ARCH_SET_FS.  */
# include <stdbool.h>
# include <stddef.h>
# include <stdint.h>
# include <stdlib.h>


/* Type for the dtv.  */
typedef union dtv {
  size_t counter;
  struct {
    void *val;
    bool is_static;
  } pointer;
} dtv_t;


typedef struct {
  void *tcb;            /* Pointer to the TCB.  Not necessary the
                           thread descriptor used by libpthread.  */
  dtv_t *dtv;
  void *self;           /* Pointer to the thread descriptor.  */
  int multiple_threads;
  uintptr_t sysinfo;
  uintptr_t stack_guard;
  uintptr_t pointer_guard;
} tcbhead_t;

#else /* __ASSEMBLER__ */
# include <tcb-offsets.h>
#endif // ifndef __ASSEMBLER__


/* We require TLS support in the tools.  */
#ifndef HAVE_TLS_SUPPORT
# error "TLS support is required."
#endif // ifndef HAVE_TLS_SUPPORT

/* Signal that TLS support is available.  */
#define USE_TLS     1

/* Alignment requirement for the stack.  */
#define STACK_ALIGN 16


#ifndef __ASSEMBLER__

/* Get system call information.  */
# include <sysdep.h>


/* Get the thread descriptor definition.  */
# include <nptl/descr.h>

# ifndef LOCK_PREFIX
#  ifdef UP
#   define LOCK_PREFIX /* nothing */
#  else // ifdef UP
#   define LOCK_PREFIX "lock;"
#  endif // ifdef UP
# endif // ifndef LOCK_PREFIX

/* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
   because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
   struct pthread even when not linked with -lpthread.  */
# define TLS_INIT_TCB_SIZE  sizeof(struct pthread)

/* Alignment requirements for the initial TCB.  */
# define TLS_INIT_TCB_ALIGN __alignof__(struct pthread)

/* This is the size of the TCB.  */
# define TLS_TCB_SIZE       sizeof(struct pthread)

/* Alignment requirements for the TCB.  */
# define TLS_TCB_ALIGN      __alignof__(struct pthread)

/* The TCB can have any size and the memory following the address the
   thread pointer points to is unspecified.  Allocate the TCB there.  */
# define TLS_TCB_AT_TP      1


/* Install the dtv pointer.  The pointer passed is to the element with
   index -1 which contain the length.  */
# define INSTALL_DTV(descr, dtvp) \
  ((tcbhead_t *)(descr))->dtv = (dtvp) + 1

/* Install new dtv for current thread.  */
# define INSTALL_NEW_DTV(dtvp) \
  ({ struct pthread *__pd;     \
     THREAD_SETMEM(__pd, header.dtv, (dtvp)); })

/* Return dtv of given thread descriptor.  */
# define GET_DTV(descr) \
  (((tcbhead_t *)(descr))->dtv)


/* Macros to load from and store into segment registers.  */
# define TLS_GET_FS() \
  ({ int __seg; __asm("movl %%fs, %0" : "=q" (__seg)); __seg; })
# define TLS_SET_FS(val) \
  __asm("movl %0, %%fs" ::"q" (val))


/* Code to initially initialize the thread pointer.  This might need
   special attention since 'errno' is not yet available and if the
   operation can cause a failure 'errno' must not be touched.

   We have to make the syscall for both uses of the macro since the
   address might be (and probably is) different.  */
# define TLS_INIT_TP(thrdescr, secondcall)                              \
  ({ void *_thrdescr = (thrdescr);                                      \
     tcbhead_t *_head = _thrdescr;                                      \
     int _result;                                                       \
                                                                        \
     _head->tcb = _thrdescr;                                            \
     /* For now the thread descriptor is at the same address.  */       \
     _head->self = _thrdescr;                                           \
                                                                        \
     /* It is a simple syscall to set the %fs value for the thread.  */ \
     asm volatile ("syscall"                                            \
                   : "=a" (_result)                                     \
                   : "0" ((unsigned long int)__NR_arch_prctl),          \
                   "D" ((unsigned long int)ARCH_SET_FS),                \
                   "S" (_thrdescr)                                      \
                   : "memory", "cc", "r11", "cx");                      \
                                                                        \
     _result ? "cannot set %fs base address for thread-local storage" : 0; })


/* Return the address of the dtv for the current thread.  */
# define THREAD_DTV()      \
  ({ struct pthread *__pd; \
     THREAD_GETMEM(__pd, header.dtv); })


/* Return the thread descriptor for the current thread.

   The contained asm must *not* be marked volatile since otherwise
   assignments like
        pthread_descr self = thread_self();
   do not get optimized away.  */
# define THREAD_SELF                                      \
  ({ struct pthread *__self;                              \
     asm ("movq %%fs:%c1,%q0" : "=r" (__self)             \
          : "i" (offsetof(struct pthread, header.self))); \
     __self; })

/* Magic for libthread_db to know how to do THREAD_SELF.  */
# define DB_THREAD_SELF_INCLUDE <sys/reg.h>  /* For the FS constant.  */
# define DB_THREAD_SELF         CONST_THREAD_AREA(64, FS)

/* Read member of the thread descriptor directly.  */
# define THREAD_GETMEM(descr, member)                                    \
  ({ __typeof(descr->member) __value;                                    \
     if (sizeof(__value) == 1) {                                         \
       asm volatile ("movb %%fs:%P2,%b0"                                 \
                     : "=q" (__value)                                    \
                     : "0" (0), "i" (offsetof(struct pthread, member))); \
     } else if (sizeof(__value) == 4) {                                  \
       asm volatile ("movl %%fs:%P1,%0"                                  \
                     : "=r" (__value)                                    \
                     : "i" (offsetof(struct pthread, member)));          \
     } else {                                                            \
       if (sizeof(__value) != 8) {                                       \
         /* There should not be any value with a size other than 1,	      \
            4 or 8.  */                                         \
         abort();                                               \
       }                                                        \
                                                                \
       asm volatile ("movq %%fs:%P1,%q0"                        \
                     : "=r" (__value)                           \
                     : "i" (offsetof(struct pthread, member))); \
     }                                                          \
     __value; })


/* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
# define THREAD_GETMEM_NC(descr, member, idx)                                 \
  ({ __typeof(descr->member[0]) __value;                                      \
     if (sizeof(__value) == 1) {                                              \
       asm volatile ("movb %%fs:%P2(%q3),%b0"                                 \
                     : "=q" (__value)                                         \
                     : "0" (0), "i" (offsetof(struct pthread, member[0])),    \
                     "r" (idx));                                              \
     } else if (sizeof(__value) == 4) {                                       \
       asm volatile ("movl %%fs:%P1(,%q2,4),%0"                               \
                     : "=r" (__value)                                         \
                     : "i" (offsetof(struct pthread, member[0])), "r" (idx)); \
     } else {                                                                 \
       if (sizeof(__value) != 8) {                                            \
         /* There should not be any value with a size other than 1,	      \
            4 or 8.  */                                           \
         abort();                                                 \
       }                                                          \
                                                                  \
       asm volatile ("movq %%fs:%P1(,%q2,8),%q0"                  \
                     : "=r" (__value)                             \
                     : "i" (offsetof(struct pthread, member[0])), \
                     "r" (idx));                                  \
     }                                                            \
     __value; })


/* Loading addresses of objects on x86-64 needs to be treated special
   when generating PIC code.  */
# ifdef __pic__
#  define IMM_MODE "nr"
# else // ifdef __pic__
#  define IMM_MODE "ir"
# endif // ifdef __pic__


/* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
# define THREAD_SETMEM(descr, member, value)                  \
  ({ if (sizeof(descr->member) == 1) {                        \
       asm volatile ("movb %b0,%%fs:%P1" :                    \
                     : "iq" (value),                          \
                     "i" (offsetof(struct pthread, member))); \
     } else if (sizeof(descr->member) == 4) {                 \
       asm volatile ("movl %0,%%fs:%P1" :                     \
                     : IMM_MODE(value),                       \
                     "i" (offsetof(struct pthread, member))); \
     } else {                                                 \
       if (sizeof(descr->member) != 8) {                      \
         /* There should not be any value with a size other than 1,	      \
            4 or 8.  */                                       \
         abort();                                             \
       }                                                      \
                                                              \
       asm volatile ("movq %q0,%%fs:%P1" :                    \
                     : IMM_MODE((unsigned long int)value),    \
                     "i" (offsetof(struct pthread, member))); \
     } })


/* Set member of the thread descriptor directly.  */
# define THREAD_SETMEM_NC(descr, member, idx, value)            \
  ({ if (sizeof(descr->member[0]) == 1) {                       \
       asm volatile ("movb %b0,%%fs:%P1(%q2)" :                 \
                     : "iq" (value),                            \
                     "i" (offsetof(struct pthread, member[0])), \
                     "r" (idx));                                \
     } else if (sizeof(descr->member[0]) == 4) {                \
       asm volatile ("movl %0,%%fs:%P1(,%q2,4)" :               \
                     : IMM_MODE(value),                         \
                     "i" (offsetof(struct pthread, member[0])), \
                     "r" (idx));                                \
     } else {                                                   \
       if (sizeof(descr->member[0]) != 8) {                     \
         /* There should not be any value with a size other than 1,	      \
            4 or 8.  */                                         \
         abort();                                               \
       }                                                        \
                                                                \
       asm volatile ("movq %q0,%%fs:%P1(,%q2,8)" :              \
                     : IMM_MODE((unsigned long int)value),      \
                     "i" (offsetof(struct pthread, member[0])), \
                     "r" (idx));                                \
     } })


/* Atomic compare and exchange on TLS, returning old value.  */
# define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \
  ({ __typeof(descr->member) __ret;                               \
     __typeof(oldval) __old = (oldval);                           \
     if (sizeof(descr->member) == 4) {                            \
       asm volatile (LOCK_PREFIX "cmpxchgl %2, %%fs:%P3"          \
                     : "=a" (__ret)                               \
                     : "0" (__old), "r" (newval),                 \
                     "i" (offsetof(struct pthread, member)));     \
     } else {                                                     \
       /* Not necessary for other sizes in the moment.  */        \
       abort();                                                   \
     }                                                            \
     __ret; })


/* Atomic set bit.  */
# define THREAD_ATOMIC_BIT_SET(descr, member, bit)                   \
  (void)({ if (sizeof((descr)->member) == 4) {                       \
             asm volatile (LOCK_PREFIX "orl %1, %%fs:%P0"            \
                           ::"i" (offsetof(struct pthread, member)), \
                           "ir" (1 << (bit)));                       \
           } else {                                                  \
             /* Not necessary for other sizes in the moment.  */     \
             abort();                                                \
           } })


# define CALL_THREAD_FCT(descr)                                        \
  ({ void *__res;                                                      \
     asm volatile ("movq %%fs:%P2, %%rdi\n\t"                          \
                   "callq *%%fs:%P1"                                   \
                   : "=a" (__res)                                      \
                   : "i" (offsetof(struct pthread, start_routine)),    \
                   "i" (offsetof(struct pthread, arg))                 \
                   : "di", "si", "cx", "dx", "r8", "r9", "r10", "r11", \
                   "memory", "cc");                                    \
     __res; })


/* Set the stack guard field in TCB head.  */
# define THREAD_SET_STACK_GUARD(value) \
  THREAD_SETMEM(THREAD_SELF, header.stack_guard, value)
# define THREAD_COPY_STACK_GUARD(descr) \
  ((descr)->header.stack_guard          \
     = THREAD_GETMEM(THREAD_SELF, header.stack_guard))


/* Set the pointer guard field in the TCB head.  */
# define THREAD_SET_POINTER_GUARD(value) \
  THREAD_SETMEM(THREAD_SELF, header.pointer_guard, value)
# define THREAD_COPY_POINTER_GUARD(descr) \
  ((descr)->header.pointer_guard          \
     = THREAD_GETMEM(THREAD_SELF, header.pointer_guard))
#endif /* __ASSEMBLER__ */
#endif  /* tls.h */
